A known amplifier of this kind has two angle levers which are arranged in mirror-image relation with respect to the plane of symmetry. The angle levers are each mounted pivotally in a housing about a respective axis and at the end of each of their lever arms they each carry a respective roller which is rotatable about an axis on the lever (see U.S. Pat. No. 2,443,775). The wedge configuration of the primary member acts on the rollers which are arranged on the longer lever arms of the angle levers, and thus pivots each lever about its mounting axis. The second roller which is provided on the shorter lever arm presses against a pin which is mounted displaceably in the housing and which forms the secondary member. The two secondary members act on the movable clamping jaw of a screw vice. This known mechanical amplifier is expensive to produce, as it consists of a large number of individual components. The axis members about which the rollers are mounted rotatably and also the mounting axis members for the angle levers are subjected to considerable forces and therefore also suffer from severe wear. As they can be subjected to only a limited loading, this known mechanical amplifier is either of large size or it can be used only to produce relatively low clamping forces. The assembly costs are also comparatively high because of the large number of individual components.
The invention is based on the problem of providing a mechanical amplifier of the above-indicated kind, which is simpler in construction, which has a smaller number of individual components, which is cheaper to produce, which is of small size and which operates with a low rate of wear.